Magnetic shift register



J. o. PAIVINEN' 3,199,088

6 Sheets-Sheet 2 MAGNETIC SHIFT REGISTER Aug. 3, Original Filed Dec. 7,1953 8.454 @558 no: my 3. 39 8 m m v r 5. 5 mt R5 r I 1: 5 w 5 5 mm om.2 8 N 3 mm 9. Q. h m: 2. 8 v: Q. m n E. 2 mm mm 5 2 mm mm mm Na wfiw a.P2: 06 mm m mm hm -09 Aug. 3, 1965 J. o. PAlVINEN 3,199,088

MAGNETIC SHIFT REGISTER Original Filed Dec. 7, 1955 6 Sheets-Sheet 3PULSE SOURCE I70 I45 ADV CU QE P 29B 299 IN VEN TOR.

JOHN OVPAIVINEN BY ATTORNEYS g- 3, 1965 J. o. PAIVINEN 3,199,033

MAGNETIC SHIFT REGISTER Original Filed Dec. 7, 1953 6 Sheets-Sheet 4 44oADVANCEA PULSE souRcE 446 wvmcs e PULSE sounce Q 200 LU 1 d Fig. \0 3TIME MILLISECONDS ADVANCE A PULSES 200 E Fig r; I00

j 0 5 IO v so 2 nue MILLISECONDS ADVANCE B PULSES INVENTOR. JOHN O.PAIVINEN ATTORNEYS 6 Sheets-Sheet 5 Original Filed Dec. 7, 1953 mmm NNm

mww hum nmw Nm WM EN R Aug. 3, 1965 J. o. PAIVINEN MAGNETIC SHIFTREGISTER 6 Sheets-Sheet 6 Opiginal Filed Dec. 7, 1953 wumDOm wwJDaINVENTOR.

JOHN 0. PAIVINEN ATTORNEYS United States Patent 3,199,088 MAGNETIC SHIFTREGISTER John 0. Paivinen, Palo Alto, Calif., assignor to BurroughsCorporation, Detroit, Mich, a corporation of Michigan Continuation ofapplications Ser. Nos. 396,603 and 396,605, Dec. 7, 1953, and Ser. No.420,135, Mar. 31, 1954. This application Sept. 23, 1958, Ser. No.762,863

93 Claims. (Cl. 340-174) This application is a continuation of threeearlier-filed, co-pending applications, Serial Nos. 396,603, 396,605 and420,135 all now abandoned. The first, entitled Magnetic Shift Register,and the second, entitled Magnetic Device, were filed December 7, 1953.The third, also entitled Magnetic Device, was filed March 31, 1954 as acontinuation-in part of a prior application Serial No. 396,604, filedDecember 7, 1953, now abandoned. All of these applications were filed inthe name of the present inventor, John O. Paivinen. I

This invention relates generally to registers and more specifically toshift registers which utilize magnetic elements as the means of storinginformation.

In the computing and business machine art, information storing registersare of considerable importance. Often it is desirable to storeinformation in a register and subsequently to shift the informationalong from stage to stage in said register. Several types of registersare known in the prior art including mechanical, electromechanical,electronic, and magnetic shift registers. In many instances, due totheir ability to maintain stored information without a constantlyavailable power source and their substantially unchanging operatingcharacteristics with wear and age, magnetic shift registers present themost advantages for particular applications. The known magnetic shiftregisters utilizing only two magnetic elements per stage are capable ofshifting information in one direction only. A magnetic shift registerutilizing two magnetic elements per stage and capable of shiftinginformation in two directions would mark a definite improvement in theart.

Magnetic switching elements having cores, which exhibit a substantiallyrectangular hysteresischaracteristic, have been used in shift registersof the prior art in the manner disclosed by A. D. Booth in an articleentitled, An Electronic Digital Computer, appearing in ElectronicEngineering, for December. 1950. The switching elements tend to remainin one or the other permanent magnetic remancnce condition after beingdriven into magnetic saturation by signals presented at a winding aboutthe element. The two states of magnetic remanence provided by thesecores enable them to efficiently store binary information and retain itstatically until it is removed. When an element is in one remanencecondition. little voltage will be induced in the windings about theelement by input signals of a polarity tending to establish the sameremanence condition in the element. However. when the input signal isopposite in polarity to the storage state of the element, a high outputvolt-age is induced in windings about the core element. Therefore, theelements may be interrogated with a signal of known polarity todetermine their remanence condition and thereby read out the storedinformation. When this is done the core is reset to a predeterminedremanence state which permits it to selectively receive further inputinformation.

In these magnetic elements a signal is induced in all of the windingswhen the element is interrogated. Accordingly, magnetic storage elementshave required external gating means for permitting transfer of theinformation only during the desired interrogation period. Although theinformation could be read out of a core into 3,199,088 Patented Aug. 3,1965 "ice several circuits at the same time, there has been no internalconditional transfer means in the prior art provided for readingselectively into separate specified circuits which are coupled todifferent output windings about any one element. I

Accordingly, it is an object of the present invention to effectconditional transfer from static magnetic storage elements.

Another object of the present invention is to provide an improved shiftregister capable of shifting information in two directions.

A general object of the invention is to provide improved magneticstorage elements.

A further object of the invention is the improvement of shift registersgenerally.

In general the invention provides means for conditionally transferringinformation from one magnetic core to another, one of which may bereferred to as the transj' mitting core and the other as the receivingcore. This is effected by providing two branch current flow paths in acoupling circuit between the magnetic core elements. Current flowthrough two such branch current flow paths acts to apply opposingmagnetizing forces to at least the receiving core element. The opposingmagnetizing forces are generally equal in magnitude when the two coreelc ments are in a static condition. Thus, a conditional enablingcurrent may be passed through the branch paths from an external sourcewithout disturbing the static storage condition in the cores. induced inone of the windings in the transfer loop as a result of the flux changein the transmitting core while that core is being switched from onestate to another during a dynamic switching operation, the current flowis unbalanced in the two branch paths so as to apply unbalancedmagnetizing forces to the receiving core enough to establish asaturating magnetic flux in such receiving element so that theinformation is in effect transferred from thetransmitting element to thereceiving element. A pair of rectifiers are provided, one in each of thebranch current paths, to pass the enabling current through each pathbetween the elements in the same direction, so that there can be nocirculating current flow in the loop. In this manner, .therefore,information may be transferred from one element to another only whencurrent is flowing inthe transfer loop from the external source.Therefore, by passing cur-rent through the loop only during theadvancing period, positive transfer of the information from one elementto another is conditionally effected without coupling noise orinformation generated in the windings of I either element during otherswitching conditions.

In accordance with another feature of the invention, a one stageregister may readily be adapted to perform the function of a pulsetransmitting magnetic core and a pulse receiving magnetic core whereinthere will be no spurious output signals from said receiving magneticcore when a pulse is transmitted thereto from the pulse transmittingmagnetic core.

In accordance with one embodiment of the invention the magnetic shiftregister is comprised of a plurality of magnetic cores arranged'in a rowand a plurality of an end terminal of the tapped output winding to anend terminal of the tapped input winding, and a second asymmetricalconducting device connects the other end terminal of the tapped outputwinding to the other end terminal of the tapped input winding, the firstand second asymmetrical conducting devices being connected so that theirBy means of potential I respective anodes are connected to end terminalsof the same winding. Advance windings are individually wound on each ofsaid plurality of magnetic cores. Each of said advance windings isconnected to the tap of one of the windings of the next succeedingcoupling circuit and to the trip of one of the winding of alternatingcoupling circuits. A first energizing source is provided to applyelectrical pulses on a terminal of the advance winding of first magneticcore in the row of cores and a second energizing source is provided toapply electricalpulses on a terminal of the advance winding of thesecond magnetic core in said row. In this manner, current is passedthrough the intermediate transfer loop between the cores in timecoincidence with the advancing or interrogation operation.

In accordance with a second embodiment of the invention similar couplingcircuits are provided between the various magnetic cores arranged in arow and, in addition, a second coupling circuit is added betweeen eachpair of adjacent magnetic cores. Each of these additional couplingcircuits is similar to the coupling circuits of the first embodiment butthese coupling circuits are connected in reverse order. Also, each coreis provided with an additional advance winding. Corresponding terminalsof each of the additional advance windings are connected to theadditional coupling circiuts in the same manner as in the firstembodiment. A third energizing source is adapted to apply electricalpulses on a terminal of the added advance winding of the last magneticcore in the row of magnetic cores and a fourth energizing source isprovided to apply electrical pulses on a terminal of the advance windingof the second to last magnetic core in the row of magnetic cores.

In accordance with a third embodiment of the invention I the magneticshift register is comprised of a plurality of magnetic cores arranged ina row together with a coupling circuit connecting each adjacent pair ofcores, which coupling circuit comprises an output winding on each coreand a tapped input winding on the next succeeding magnetic core. Oneterminal of each of the output windings is connected to oneend terminalof the associated tapped input winding and the other terminal of each ofsaid output windings is connected to the other end terminal of theassociated input winding by circuit means. Such circuit means mayinclude a first asymmetrical conducting device and a second asymetricalconducting device connected in such a manner that either the anode orthe cathode of said first asymmetrical conducting device is connected tothe said second terminal of the associated winding and the correspondingelectrode of the said second asymmetrical conducting device is connectedto the said second end terminal of the associated tapped input winding.Where many cores are included in the shift register, each junctionbetween the first and second asymmetrical devices of each of saidcoupling means is connected to the tap of the tapped input windingassociated with the magnetic core immediately preceding the two magneticcores coupled together by the coupling means including the associatedjunction. Means are provided to apply electrical impulses to the taps ofthe said tapped input windings associated with the last magnetic core insaid row and the next to last magnetic core in said row.

In accordance with a fourth embodiment of the invention hereinidentified as a reversible magnetic shift register the same structure ispresent as described in the said third embodiment of the invention andin addition there is comprised a second plurality of coupling meanssimilar to the first plurality of coupling means, each of said secondplurality of coupling means coupling together adjacent ones of saidmagnetic cores. Each of said second plurality of coupling means beingconnected in reverse mannor to that of each of said first plurality ofcoupling means in that the first winding means are wound on individualmagnetic cores and the associated tapped second winding means is woundon the immediately preceding magnetic core. Moreover, where many coresare employed, the junctions between the two asymmetrical devices of anycoupling means of the second plurality is connected to the tap of thewinding wound onthe magnetic core immediately following the two magneticcores coupled toart magnetic shift registers are known to exist which donot utilize rectifiers of one type or another between stages. It wouldbe advantageous therefore to have a magnetic shift register whicheliminates the necessity of rectifiers inasmuch as rectifiers in suchregisters have been frequently unreliable because of their tendency tofail.

To this end anadditional object of the present inventionis to rovide amagnetic shift register avoiding the necessity of rectifiers.

A further important object of the invention in this regard is to providean improved magnetic shift register employing circuit coupling meansbetween each pair of magnetic cores including a Wheatstone bridge typeof transfer circuit.

In accordance with these objects of the invention, in a furtherembodiment of the invention a plurality of magnetic cores are arrangedin a row and adjacent ones of the cores are coupled together by transfercircuits, each of which comprises an output winding on a given magneticcore, an input winding on the next adjacent magnetic core, and asubstantially balanced bridge circuit comprising as its four legs afirst impedance, a second impedance, a third impedance, and a fourthimpedance, of which two of the impedances are of a non-linear type whoseresistance will change with changes in the amount of electric currentflow therethrough. The end terminals of each output winding areconnected across two opposite terminals of the bridge circuit and theend terminals of the input winding-are connected across the other twoterminals of the bridge circuit. The bridge is so arranged that each ofits four terminals has presented thereto a linear and a non-linearimpedance. A third winding is wound on each of the magnetic cores. Eachof the third windings is connected to a tap of one of the windings ofthe next succeeding transfer circuit and to a tap on one of the windingsof alternate transfer circuits.

Thus, no asymmetrical conducting devices are utilized in this device butrather a bridge circuit, which becomes unbalanced when a sufiicientlylarge current is passed therethrough, is utilized to effect shifting ofstored information through the register from one stage to a succeedingstage.

These and other objects, advantages and features of the invention willbe more fully understood from the following detailed description of theinvention when read in conjunction with the drawings, in which:.

FIGS. 1 and 2 are schematic diagrams of embodiments of the inventionutilizing one diode in each of two parallel branches of the transfercircuit between cores. In FIG. 2 information can be shifted in twodirections;

FIGS. 3 and 4 show typical waveforms of advance A pulses and advance Bpulses for use in connection with the circuits of FIGS. 1 and 2;

FIGS. 5 to 7 show schematic diagrams of different embodiments of theinvention;

FIGS. 8 and 9 are schematic diagrams of embodiments of the inventionalso utilizing a diode in each of two parallel branches of the transfercircuit between cores. In FIG. 9 information can be shifted in twodirections;

FIGS. 10 and 11 show typical advance A and advance B pulses for use inthe FIG. 8 and 9 embodiments; and

FIG. 12 is a schematic diagram of a further embodiment of the inventionutilizing an impedance bridge in the transfer circuits between cores.

Referring now to FIG. 1, magnetic cores 108, 109, 110, and 111constitute the storage means for information contained in the registerand are composed of magnetic material having a substantially square wavehysteresis loop. Tapped input windings 10, 11, 12, and 13, which may ormay not be center tapped, are wound respectively on cores 108, 109, 110and 111. Tapped output windings 14, 15, 16 and 17 are wound respectivelyon cores 108, 109, 110, and 111. Adjacent magnetic cores are coupledtogether by coupling circuits. For example, cores 108 and 109 arecoupled together by coupling circuits comprising tapped output winding14, tapped inut winding 11, asymmetrical conducting devices 22 and 25,and resistors 28 and 31.

In the operation of the device, thus far described, the storedinformation is shifted along from magnetic core to magnetic core byalternate advance A and advance B pulses, derived from pulse sources 150and 151, respectively, to apply current flow through conductors 39 and40 to conductors 122 and 125. The circuit for the advance A pulse may betraced from the terminal to which the conductor 39 is connected, throughwinding 18, conductor 120, the parallel circuit comprising winding 11,asymmetrical conducting devices 22 and 25, resistors 28 and 31, andwinding 14 of magnetic core 108, then through conductor 118, winding 20of magnetic core 110, conductor 119, the parallel combination of winding13, resistors 30 and 33, asymmetrical conductive devices 24 and 27, andwinding 16 of magnetic core 110, and then through conductor 122 back toadvance A pulse source 150. The circuit for the advance B pulse can betraced from the terminal to which the conductor 40 is connected throughwinding 19 of magnetic core 109, conductor 123, the parallel combination of winding 12 of magnetic core 110, the resistors 29 and 32,asymmetrical conductive devices 23 and 26, and winding of magnetic core109, then through conductor 124, winding 21 of magnetic core 111, andconductor 125 back to advance B pulse source 151.

In one preferred embodiment of the invention the following values andmaterials may be used. The mag netic cores have a cross-sectional areaof about 0.00028 square inch, and a mean circumference of about 0.375inch. The material used in the magnetic cores can be molypermalloy orany other suitable magnetic material having a substantially rectangularhysteresis loop. Tapped windings 10, 11, 12, and 13 each have 30 turns.Tapped output windings 14, 15, 16, and 17 each have 90 turns andwindings 18, 19, 20, and 21 each have 23 turns. Asymmetrical conductivedevices 22, 23, 24, 25, 26, and 27 are of the germanium diode typealthough other type asymmetrical conductive devices may be used.Resistors 28, 29, 30, 31, 32, and 33 each have a value of 18 ohms. Theadvance A pulses and the advance B pulses each have a duration of about10 microseconds and an amplitude of about 200 milliamperes. It is to benoted that the above values may be changed in accordance with differentdesired designs.

Referring now to FIG. 2, there is shown a reversible magnetic shiftregister. The circuitry below the dotted line is the same as thecircuitry shown in FIG. 1. More specifically, input windings 50, 51, 52,and 53 of FIG. 2 correspond to input windings 10, 11, 12, and 13 ofFIG. 1. Output windings 58, 59, 60, and 61 of FIG. 2 correspond tooutput windings 14, 15, 16, and 17 of FIG. 1. Windings 54, 55, 56, and57 of FIG. 2 correspond to windings 18, 19, 20, and 21 of FIG; 1.Asymmetrical conductive devices 78, 79, 80, 84, 85, and 86 correspond toasymof FIG. 2 is adapted to shift the stored information in a forwarddirection from left to right in the drawing. .The advance A'pulse source173 is connected to the tap of winding 60 and to an end terminal ofwinding 54 by means of conductors 103 and 102. The advance B pulsesource 174 is connected to the end terminals of windings 55 and 57 bymeans of conductors 216 and 104. Information is entered into theregister by means of input pulse source 181 which is connected to inputwinding 50.

The circuitry above the dotted line in FIG. 2 is also the same as thecircuitry in FIG. 1 except that it is reversed in order to shift thestored information in the opposite or reverse direction, i.e., fromright to left instead of from left to right. Input windings 74, 73, 72,and 71 of FIG. 2 correspond respectively to input windings 10, 11, 12,and 13 of FIG. 1; output windings 66, 65, 64, and 62 of FIG. 2correspond respectively to output windings 14, 15, 16, and

17 of FIG. 1; and windings 70, 69, 68, and 67 of FIG. 2-

correspond respectively to windings 18, 19, 20, and 21 of FIG. I.Asymmetrical conductive devices 910, 91, 90, 97,

96, and of FIG. 2 correspond respectively to asymmetrical conductivedevices 22, 23, 24, 25, 26, and 27 of FIG. 1 and resistors 89, 88, 87,94, 93, and 92 correspond respectively to resistors 28, 29, 30, 31, 32,and 33 of FIG. 1. A load or utilization circuit 177 is connected acrossthe winding 62. As can be seen from a comparison of FIGS. 1 and 2 thepolarities of the asymmetrical devices of the circuitry above the dottedline in FIG. 2 are reversed from those of FIG. 1, although operation isidentical with the asymmetrical devices connected in either polarity,the only difference being the direction of current flow through therespective circuits. Advance A pulse source 175 is connected to windings67 and 69 by means of conductors and 127 and the advance B pulse source176 is connected to the tap of winding 64 and a terminal of winding 70by means of conductors 106 and 107. Information is entered into thecircuit by means of input source 180 which is connected to input winding74.

The values of the circuit constants, the number of turns of thewindings, and the material and dimensions of the magnetic cores 112,113, 114, and of the typical embodiment of the invention shown in FIG. 2may be the same as the corresponding elements described in connectionwith FIG. 1.

v The manner in which noise generated in one of the magnetic elements isisolated is discussed in connection with FIG. 5, wherein information canbe transferred from a transmitting magnetic core to a receiving magneticcore 136 without creating spurious output signals in said receiving corein response to other operations within the transmitting core. In the.embodiment of FIG. 5, magnetic core 137 constitutes the load of thedevice. Input winding 138 of core 135 is adapted to be energized .by thesource 171. The split output winding 139-140 of core 135 has its endterminals connected to the end terminals of the split input winding142-143 of core 136 through asymmetrical conductive devices 147 and 148.The split output winding 144-172 of core 136 has its end terminalsconnected through two additional asymmetrical devices to the endterminals of the split winding 145-146 wound on magnetic core 137. Pulsesource 149 is connected be-- tween a first terminal of winding 141 andthe tap of split winding 142-143 of core 136. The second terminal of 7winding 150 is connected to the center tap of winding 144-172.

Referring now to FIG. 1, the operation of the circuit shown therein willbe described in detail. Assume that ordinarily inf ormationis stored inthe A cores, i.e., magnetic cores 108 and 110. To shift a bit of storedinformation from core 108 to core 110 it is necessary to store ittemporarily in B core 109. Assume that a binary bit of O is stored inmagnetic core 108 which will be in a condition of negative remanence asarbitrarily indicatcd by magnetic fiux of a direction opposite that ofthe arrow 152. Assume further that a binary bit of "1 is stored inmagnetic core 110 which will be in a condition of positive remanence asindicated by magnetic flux in the direction of the arrow 54. B magneticcores 109 and 111 will be in a state of negative remanence as indicatedby magnetic flux in a direction opposite that of the arrows 153 and 155.If now a pulse is applied from the advance A pulse source 150 a currentmay be traced through conoductor 122, to the tap of winding 16. At thispoint, the current splits into two substantially equal parts during theperiod that the core remains in a static condition to apply equal andopposite magnetizing forces to the core. One part of the current flowsthrough the upper half of the winding 16, asymmetrical conductive device24, resistor 30, the upper half of the winding 13, to the tap of winding13. The other part of the current flows through the lower half ofwinding 16, asymmetrical conductive device 27, resistor 33, the lowerhalf of winding 13, to the tap of winding 13. The current path thencontinues through conductor 119, winding of magnetic core 110, conductor118, to the tap of winding 14 of core 108. At this point, the currentagain splits into two equal parts; one part flowing through the upperhalf of winding 14, through asymmetrical conductive device 22, resistor28, the upper half of winding 11 to the tap of winding 11; and the otherpart of the current flowing through the lower half of winding 14,asymmetrical conductive device 25, resistor 31, the lower half ofwinding 11, to the tap of winding 11. The current path continues fromthe tap of winding 11 through conductor 120, winding 18 of core 108, andthrough conductor 39 back to the advance A pulse source 150.

It is to be noted that the advance current into the output windings 14and 16 is at the taps and that the exit of the current from the inputwindings 11 and 13 is also at the taps of said input windings 11 and 13.Therefore, with center tapped windings, when the resistance of thediodes 24 and 27 are equal and the resistances 30 and 33 are equal, theelectrical currents flowing through the two parallel paths joining thecenter tap of winding 16 with the center tap of winding 13 will besubstantially equal. If, however, the current flow through winding 20 ofcore 110 causes the magnetic flux in the magnetic core 110 to changefrom positive remanence to negative saturation, a voltage will beinduced in winding 16 of core 110 having its positive polarity onterminal 128 of winding 16 which will cause a positive current to flowin a circuit path extending from winding 16, through asymmetrical device24, resistance 30, winding 13, resistance 33, asymmetrical device 27,and back to winding 16. This current is superimposed upon the advance Acurrent. It is to be noted that ordinarily no appreciable current willflow through asymmetrical device 27 in a right to left direction.However, a decrease in the advance A current which is flowing in theopposite direction through the asymmetrical device 27 will be equivalentto a current flow in such direction. Thus, the effect of having theinduced current flow in the direction of the high back impedance ofasymmetrical device 27 is obtained. In actuality the advance A currentthrough asymmetrical device 27 and the induced current flow therethroughhave opposite polarities and tend to cancel each other out. The inducedcurrent and the advance A current flowing through asymmetrical device 24add together so that the current flow through the upper half of winding13 of core 111 is much greater than the current flow through the lowerhalf of winding 13. This difference in current flow is made suflicicntto cause the magnetic flux in magnetic core 111 to switch to a conditionof positive saturation, and, upon cessation of the current pulse, torelax to a condition of positive remnanence, thus effectivelytransferring the binary bit of 1 from magnetic core to magnetic core111. As noted above, the magnetic core 110 was caused to assume acondition of negative remanence during this process.

A binary bit of 0 was stored in magnetic core 108.

Consequently, when the advance A current pulse flows v through winding18 of core 108 the magnetic flux of core 108 is caused to change from anegative remanence to a negative saturation, and, upon cessation of theadvance A pulse to relax to negative remanence. The voltage therebyinduced in winding 14 is not great enough to unbalance the advance Acurrent pulse flowing in the two halves of winding 11 to cause anappreciable change of magnetic flux in magnetic core 109. Thus, core 109remains in a state of negative rcmnance as does core 108 and the binarybit of 0 has been effectively transferred from core 108 to core 109.

If now an advance B pulse is applied to lead 40 from source 151, theinformation stored in magnetic core 109 will be transferred to magneticcore 110 and the information stored in magnetic core 111 will betransferred out of core 111 into output winding 17 and the load 130,which could be another magnetic core element. The circuit for advancepulse B may be traced through conductor 125, winding 21 of magnetic core111, conductor 124, to the tap of winding 15 of core 109. At the saidtap, the current splits into two substantially equal parts; one partflowing through asymmetrical device 23 and resistance 29 to the tap ofwinding 12, and the other part flowing through asymmetrical device 26and resistance 32 to the tap of winding 12. From the tap of winding 12,the current fiows through conductor 123, winding 19, conductor 40, andback to the advance B pulse source 151. The binary bit of 1 stored inthe core 111 and represented by a condition of positive remnance in core111, is transferred to the load when the advance B pulse flowing throughwinding 21 causes the magnetic flux to change from a condition ofpositive remnance to a condition of negative saturation. The advance Bcurrent flow from the tap of winding 15 to the tap of winding 12 isdivided substantially equally between the two current paths connectingthe two taps. When the advance B pulse flows through the winding 19 ofmagnetic core 109, the magnetic flux is caused to change from acondition of negative remanence to a condition of negative saturation.This change in the magnetic flux condition of magnetic core 109 isinsuflicient to induce a large enough voltage in winding 15 to cause anyappreciable change in the magnetic flux condition of magnetic core 110.Thus, the 0 bit of information stored in magnetic core 109 iseffectively transferred to magnetic core 110.

Typical advance A pulses and advance B pulses are shown in FIGS. 3 and4. The time spacing between an advance A pulse and an advance B pulsecan be zero or any longer amount of time desired.

The circuitry above the dotted line in FIG. 2 causes the information tobe shifted in the same manner as de scribed with respect to thecircuitry shown in FIG. 1, except that in FIG. 2 the circuitry above thedotted line shifts the information from right to left as discussedhereinbefore. Thus, in the circuit of FIG. 2 information can be shiftedfrom magnetic core 112 to magnetic core 114 by application of an advanceA pulse from source 173 and then an advance B pulse from source 174 uponconductors 103 and 104 respectively. If it is then desired to shift theinformation from magnetic core 114 back to magnetic core 112, this maybe accomplished by application of an advance A pulse and then an advanceB pulse upon conductors 105 and 106 respectively.

Referring to FIG. the operation of the circuit shown therein will bedescribed in detail. Assume that the arrows 272 and 273 indicate thedirection of positive magnetic flux in said magnetic cores 135 and 136.Assume further that the magnetic cores 135, 136, and 137 are in acondition of negative remanence. A positive pulse applied from source171 to terminal 161 of winding 138 will cause the magnetic core 135 toassume a condition of positive magnetic saturation. Whenv the pulsesource 149 is energized to cause a pulse to flow through the winding 141then the core 135 will be caused to assume a condition of negativeremanence upon cessation of the pulse, and the magnetic core 136 will becaused to assume a condition of positive remanence upon cessation ofsaid pulse in accordance with the description of operation of FIG. 1.There will be no output from winding 144- 172 at this time because ofthe isolation afforded by the conditional transfer nature of the outputcircuit including associated asymmetrical devices between cor-es 136 and137, which prevent circulating current flow within the transfer loop.When a pulse is applied to the winding 160 from source 170, the core 136will be caused to assume a negative remanence upon the cessation of thepulse and the load core 137 will be caused to assume a positive magneticremanence in accordance with the description of operation of FIG. 1. Inthe above example, core 135 is designated as the transmitting core andcore 136 as the receiving core. It is possible, by this arrangement,therefore, to transmit a pulse from a transmitting core 135 to areceiving core 136 without having spurious 'output voltages generated inthe output winding of the receiving core 136.

In the foregoing embodiments of the invention, the advancing windingshave been connected for operation by the same current which flowsthrough the transfer loop, so that a coincidence timing relationshipmight be effected. However, as shown in FIG. 6, such connect-ion is notnecessary in the more general operation of the invention. For thepurpose of comparing this embodiment with that shown in FIG. 5, the samereference characters are used where possible to indicate similarelements of the invention. Assume that the current I flows in thetransfer loop between elements 135and 136 in the direction establishedby orientation of the diode rectifiers 147 and 148. As before described,the current will be evenly divided in the two branches so that opposingmagnetizing forces will be applied by the split windings to both element135 and element 136, and accordingly the storage state of the coresremains undisturbed. However, when a change in the remanence conditionoccurs in core 135 by application of an advancing pulse from source 149to winding 141, a potential is induced in the entire winding 139-140,which aids the current flow in one branch and opposes the current flowin the other branch circuit, and causes a resulting unbalance ofmagnetizing force being applied to element 136 such that the remanencecondition of element 136 is changed to correspond with that informationwhich has been removed from element 135 by the advancing pulse. Thisaction will take place no matter what the polarity of the inducedpotential in the winding 139-140 and, therefore, the storage conditionof element 136 will be changed along with that of element 135 so long asthe current I flows through the transfer loop. The current may thus beconsidered an enabling condition for effecting transfer of informationfrom one element to another. In operation this device is similar to thatshown in connection with FIG. 5 in that coincidence of current flowthrough winding 141 and the transfer loop must occur in order to effecta transfer of information, even though the winding does not need to beconnected in the same current flow path. In some cases the amount ofcurrent flow through winding 141 would be different from that desiredwithin the transfer loop, and

therefore this more general embodiment of the invention aflfords morelatitude in the engineering design of the con- I ditional transfer loopsafforded by this invention.

By means of such conditional transfer loops, information may betransferred to two or more additional core William Miehle and JosephWylen, now Patent No. 2,943,-

It is noted that the rectifiers in each of the loops 301. 230 and 231are reversed with respect to one another without effect on the transferoperation. The only cr-i-' terion for transfer is the condition thatcurrent be flowing in the loops at the time the element 136 isinterrogated by the pulse source 170. In this same manner theinformation already transferred from core element to core element 136may be restored to core 135 by applying current I during the duration ofthe pulse from source 170. This specific embodiment of the invention ismore specifically described and claimed in an application by David Loev,Serial No. 452,753, filed August 30,

1954, and entitled, Reversible Shift Register, now abandoned in favor ofcontinuation application Serial No. 763,157 (now Patent No. 3,023,401).

-In order to combine the advantageous features of both the embodimentsof FIGS. 5 and 6 a further embodiment shown .in FIG. 7 is provided,wherein a minimum. number of windings are coupled in the transfer loop.In this embodiment of the invention theadvance winding 141' is made toserve both as an advance winding and as an output winding, the functionhereinbefore provided by the tapped winding 139- 140 of FIG. 5. In thecircuit of FIG. 7,the current flowing through the two sections 142 and143 of the tapped winding on element 136 during the static remanencecondition will cause current of one section or branch only to flowthrough the advance winding 141'. This will cause a change of remanencecondition in element 135 if a bit of 1 information is .stored in thecore, and accordingly upset the balance of current flowing in winding142-143 so that the information is shifted to element 136 in the mannerhereinbefore' described, However, when core 135 does not contain a bitof "1 information the current flow is substantially balanced and theloop also behaves in the same manner hereinbefore described toeifectively transfer the bit of "0 information to core 136. Since theimpedance may be slightly unbalanced in this type of circuit becausewinding 141 appears in only one of the branch paths, compensation forsuch unbalance may be had either by placing the tap of the split windingoff-center or by the use of the external resistors 298 and 299, toequalize current flow during the static remanence condition. particularembodiment of FIG. 7 is described in detail with reference to FIGS. 8and 9.

With the embodiment of FIG. 7 a slight unbalance of the windings 142 and143 may be desirable, so that the enabling current fiow through thetransfer loop 232 will more tend to send the core 136 into saturation inits preset or read-out storage state. This will permit faster switchingspeeds with the system since the enabling current of a the succeedingtransfer loop 230 need not be continued after switching of element 137until the element 136 is completely switched, but may be foreshortenedto permit the enabling current of transfer loop 232 to continue theswitching to the preset state when no information transfer occurs fromelement 135.

In each of the described embodiments of the invention, transfer ofinformation between two cores is effected by means of biasing one of thediode rectifiers in the transfer loop in a direction tending to inhibitthe flow of en- This abling current there-through, so that acorresponding unbalance of magnetizing force applied by the splitwindings causes switching of the remanence condition in the receivingcore. By selectively biasing the diodes in the transfer loop thereforeconditional transfer of information into one of several circuits may beeffected. In addition, the conditional transfer techniques taught by theinvcntion atr'ord isolation of receiving circuits from switching noisevoltages or other operational potentials developed intransmittingcircuits.

Referring more specifically to the embodiment of FIG. 8, a plurality ofmagnetic core elements 410, 411, 412 and 413 are arranged in a row whichis their usual disposition in computing equipment. Each one of the twocores has an input and an output section which may be characterized by aseparate winding on the cores. Input winding 414 and center tapped inputwindings 415, 416 and 417 are wound around the magnetic cores 410, 411,412 and 413, respectively. Input pulses are applied to the terminals ofinput winding 414. Output windings 418, 419. 426 and 421 are woundaround cores 410, 411, 412 and 413 preferably in displaced relation tothe input windings as shown.

Each of output windings 418. 419 and 429 is connected to the inputwinding of the next adjacent magnetic core through a circuit includingtwo asymmetrical conducting devices and two resistive means. Forexample, one terminal of output winding 418 of magnetic core 410 isconnected to one end terminal of input winding 415 of magnetic core 411.The other terminal of winding 418 is connected to the other end terminalof winding 415 through a circuit means comprising asymmetricalconducting device 422, resistive means 428, junction 443, resistivemeans 43l,and asymmetrical conducting device 425. The anodes ofasymmetrical devices 422 and 425 are connccted respectively to thewinding 418 and the winding 415. Junction point 443 is located betweenresistive means 428 and 431. Similar circuitry exists between outputwinding 41) of core 411 and input winding 416 of core 412 includingasymmetrical conducting devices 423 and 426. resistors 429 and 432, andjunction 444. Another similar circuit exists between output winding 420of core 412 and input winding 417 of core 413 including asymmetricalconducting devices 424 and 427, resistors 430 and 433, and junction 445.Output winding 421 of core 413 is connected to a load 442. It is to benoted that tapped input windings 415 and 417 have reference charactersthereon denoting the two portions of each tapped winding. Morespecifically, the two portions of winding 415 are denoted by referencecharacters 460 and 461 and the two portions of winding 417 by referencecharcaters 448 and 449.

An advance pulse source, herein identified as Advance A Pulse Source446, is adapted to cause a current flow through a circuit extending fromthe source through conductor 440 to the ccntar tap of input winding 417of core 413. From this center tap the current can flow in two paths tojunction 445. One of these circuits extends from the center tap ofwinding 417, through the upper half 448 of winding 417, winding 420 ofcore 412. diode rectifier or similar asymmetrically conducting device424, resistor 430, to junction 445. The other of these two circuitsextends from the center tap of winding 417, through the lower portion449 of winding 417, asymmetrical conducting device 427, resistor 433, tojunction 445. From junction 445 the advance A pulse circuit extendsthrough conductor 437 to the center tap of input winding 415 of core411. From the center tap of winding 415 the current can How in two pathsto junction 443. One of these two paths may be traced from the centertap of winding 415, through the upper portion 468 of winding 415,winding 418 of core 410, asymmetrical conducting device 442, resistor428, to junction 443. The other of these two circuits extends from thecenter lap of winding 415, through the lower portion 461 of winding 415,asymmetn'cal conducting device 425, resistor 431, to junction 443. Fromjunction 443 the advance A pulse current path can be traced throughconductor 438 to advance A pulse source 446.

A second pulse source, herein identified as Advance B Pulse Source 447,is adapted to cause a current flow through conductor 439, to the centertap of winding 416 of core 412. From the center tap of winding 416 thecurrent can flow in two paths to junction 444. A first of these twocircuits can be traced from the center tap of winding 416 through theupper portion of winding 416, winding 419 of core 411, asymmetricalconducting device 423, resistor 429, to junction 444. The second ofthese two circuits extends from the center tap of winding 416, throughthe lower portion of winding 416, asymmetrical conducting device 426,resistor 432 to junction 444. From junction 444 the advance B pulsecurrent path may be traced through conductor 441 back to the advance Bpulse source 447.

Referring now to FIG. 9, magnetic cores 550, 551', 552 and 553 may be ofthe same material, size and shape as the magnetic cores of FIG. 8. Thecircuitry below the dotted line 594 is the same as the circuitry shownin FIG. 8 and the values may also be the same. the circuitry below thedotted line 594 in FIG. 9 have the same reference number plus as thecorresponding elements of the circuitry of FIG. 8. For example winding418 of FIG. 8 corresponds to winding 518 of the circuitry below thedotted line in FIG. 9. The circuit paths for the advance A pulses andthe advance B pulses are the same as for the circuitry of FIG. 8.

It is to be noted that the device shown in FIG. 9 is a reversiblemagnetic shift register and that circuitry below the dotted line 594causes the stored information to shift from left to right while thecircuitry above the dotted.

line causes the information to shift from right to left. The circuitryabove the dotted line 594 is the same as the circuitry shown in FIG. 8except that it is reversed; i.e., for example, the input winding 414 ofcore 410 of FIG. 8 corresponds to the input winding 614 of core 553 ofFIG. 9 and output winding 421 of core 413 of FIG. 8 corresponds to theoutput winding 621 of core 550 of FIG. 9.

The circuit elements of the circuitry shown in FIG. 8 have referencecharacters of the corresponding circuit elements of the circuitry shownabove the dotted line 594 of FIG. 9 except that the reference charactersof the .circuitry shown above the dotted line in FIG. 9 have 200" addedto them. For example, the advancing pulse sources 446 and 447 andassociated circuitry correspond I to the advancing pulse sourcesrespectively.

The structure shown in both FIG. 8 and FIG. 9 can be divided into twostages which can arbitrarily be identified as stage A and stage B tocorrespond to the advance A pulse and the advance B pulse. Morespecifically, the magnetic cores which are energized directly by the adVance A pulse are herein identified as stage A cores and the magneticcores which are energized directly by the advance B pulse are hereinidentified as stage B cores, as designated in FIG. 8.

Referring again to FIG. 8 the operation of the circuit shown thereinwill be described in detail. Assume that a binary bit of 1, representedby a condition of positive remanence of the magnetic core in which it isstored, is caused to be entered into magnetic core 410 by application ofan input pulse upon input winding 414. The positive remanence conditionis indicated by the direction of arrows 462, 463, 464 and 465 in cores410, 411, 412 and 413 respectively. Assume further that all theremainder of the magnetic cores 411, 412 and 413 are in a condition ofnegative remnaence or opposite to the remanence condition represented byarrows 463, 464 and 465. If now an advance A pulse is applied toconductor 440 the binary bit of 1 stored in magnetic core 410 will betransferred to magnetic core 411, and, the binary 646 and 647 of FIG. 9

The elements of bit of O stored in magnetic core 412 will be transferredto magnetic core 413 in the following manner. The advance A pulse willflow to the center tap of winding 417. From this center tap the advanceA pulse can flow in two paths to the junction 445 as hereinbeforedescribed. The portion of the current flowing through the upper portion448 of winding 417 of core 413 and winding 420 of core 412 willencounter a substantially zero impedance in winding 420 since the saidcurrent flow therethrough will tend to cause the magnetic core 412 tobecome saturated in a negative polarity, whereas said core 412 isalready in a condition of negative remanence. The other portion of thecurrent fiOWs through the lower portion 449 of the winding 417 of core413. The resistances 430 and 433 and the upper portion 448 and lowerportion 449 of winding 17 are so proportioned that 1 4482 2 449(Equation 1) where I, is the portion of the advance A pulse flowingthrough winding 448, N is the number of turns in winding 448, I is theportion of the advance A pulse flowing through winding 449, and N is thenumber of turns in winding 449. The effect of this design is either toforce the magnetic core 413 to the negative magnetic flux state(inequality in Equation 1) or else to cause no change (equality inEquation 1). Therefore, the transfer of a binary bit of has beeneffected from the A stage magnetic core 412 to the B stage magnetic core413.

It is to be noted that the current flowing through winding 420 of core412 may induce a voltage in winding 416 if a change in magnetic fluxoccurs but that no current will flow in winding 416 due to asymmetricalconducting devices 423 and '426. Thus, no undesired reverse flow ofinformation will occur.

Returning to the path of the advance A pulse, the current will flow fromjunction 445, through conductor 437, to the tap of winding 415. -At thispoint the current can flow in two different paths to junction 443 asdescribed hereinbefore. It is to be noted that stage A core 410 containsa binary bit of 1 and this is in a condition of positive remanence andthat stage B magnetic core 411 is in .a condition of negative remanence.The portion of the advance A pulse flowing through the upper poriton 460of winding 415 encounters a high impedance in winding 418 of core 410since the said current tends to cause the magnetic flux in said core 410to change from a condition of positive remanence to a condition ofnegative saturation which, upon cessation of the current pulse, willrelax to a condition of negative remanence. As a result of this highimpedance the current flow through winding 460 is less than in the caseof a zero transfer and the current flow through winding 461 is greaterthan in the case of a zero transfer. The design of the circuit is suchthat the following equation holds true:

a 4s1 4 4so q ation where I is the portion of the advance A pulsecurrent flowing through the lower portion 461 of winding 415 and I isthe portion of the advance A pulse current flowing through the upperportion 460 of winding 415 when a high impedance state is encountered inwinding 418.

As a result of the advance A pulse and in accordance with Equation 2 thestage B core 411 will change from a condition of negative remanence to acondition of positive remanence and the core 410 will change from acondition of positive remanence to a condition of negative remanence;thus effectively transferring the binary bit of 1" from core 410 to core411. The design of the circuit further is such that core 411 will changecompletely to the positive saturation condition before core 410completely changes to a negative saturation condition. The advance Apulse is preferably terminated before core 410 completes its change tothe 0 or negative saturation condition.

Therefore, as described above, the magnetic cores in the system arereliably changed to the 1 condition (positive remanence) and corespreviously containing l s are positively returned to the 0 condition(negative remanence).

In a similar manner information temporarily stored in the stage B coresis transferred to the next succeeding stage A cores by application of anadvance B pulse upon conductor 439 from advance B pulse source 447.Since the means and the operation of transferring 0s and 1s" from astage B core to a stage A core or from a stage A core to a stage B coreare the same, a detailed explanation of the operational process oftransferring 0s and 1s from stage B cores to stage A cores is notpresented herein.

Typical advance A pulses and advance B pulses are shown in FIGS. 10 and11 respectively. The A and B. I pulses alternate with one another asshown in FIGS. 10 and 11 and should not be coincident in time. It is tobe noted that no time interval is required between successive advance Aand advance B pulses. A time interval of any desired length can be used,however.

Referring now to FIG. 9, the operation of the circuit shown therein willbe discussed. As stated hereinbefore, the circuit elements of thecircuitry of FIG. 8 corresponds to the circuit elements of the circuitrybelow the dotted line 594 of FIG. 9 having the same reference charactersbut prefixed by a 5 instead of 4. This circuitry of FIG; 9 below thedotted line 594 operates in the manner as the circuitry of FIG. 8 toshift information from left to right and the description of operation ofFIG. 8 is herein incoprorated as the description of operation of thecircuitry below the dotted line in FIG. 9.

Similarly, the circuitry above the dotted line in FIG; 9 is the same asthe circuitry in FIG. 8 except that it is connected in reverse order asexplained hereinbefore. Since the operation is the same as described inconnection 5 with FIG. 8 said operational description is hereinincorporated with-respect to the circuitry above the dotted line 594 inFIG. 9. It is to be noted that the circuit elements of FIG. 8corresponding to circuit elements of the circuitry above the dotted line594 in FIG. 9 have corresponding reference characters except that thereference characters of the circuitry above the dotted line in FIG. 9,.

are prefixed by the number 6 instead of 4.

Thus, information stored in magnetic cores is capable of being shiftedin opposite directions or either to the right or to the left by means ofthe device shown in FIG. 9.

Referring to FIG. 12, there is shown a row of magnetic cores in-thisinstance comprising four magnetic core elements 710, 711, 712 and 713.Each core is preferably formed of magnetic material having asubstantially square hysteresis loop characteristic. Each core elementhas an input and an output winding. The input windings for the cores710, 711, 712 and 713 are indicated at 714, 715,

716 and 717 respectively, and the output windings for the cores areindicated at 718, 719, 720 and 721 respectively. The input windings 715,716 and 717 are center tapped and the output windings 718, 719 and 720are center tapped. An additional winding is applied to each' Windings820, 830, 840 and 850 are wound rein which vary in accordance with theamount of current flow therethrough. Each Wheatstone bridge circuitcomprises, as customarily, four resistances. However, to accomplish theobjects of this invention two oppositely positioned resistances of thebridge circuit are of the noni linear type, i.e., the ohmic valuesthereof change with current flow therethrough. A desirable form of suchnon-linear resistance is a Thyrite element.

In the several bridge circuits the non-linear resistances are identifiedat 722 to 727 inclusive and the linear resistances at 728 to 733inclusive. The resistances 722 through 733 form a plurality ofWhcatstone bridge cir cuits, each of which couples together adjacentones of said magnetic cores. For example, core 710 is coupled to core711 by a bridge circuit comprising linear resistanccs 728 and 731 andnon-linear resistances 722 and 725. The resistances 722, 728, 725 and731 are so connected that each of the four junctions of the bridgecircuit has presented thereto a linear and a nonlinear resistance. Thetwo end terminals of output winding 718 or core 710 are connected toopposite junctions 736 and 737 respectively of the bridge circuit. Theend terminals of input winding 715 of core 711 are connectedrespectively to the other two junctions 738 and 739 respectively of thebridge circuit. Similar bridge circuits are used to couple core 711 tocore 712 and core 712 to core 713.

Two pulse sources are shown for advancing the stored information fromcore to core. Advance A pulse source 734 and advance B pulse source 735are adapted to apply electrical pulses to conductors 740 and 741respectively. The pulses from the A and B sources are applied atalternate periods of time to the shift register. The advance A pulsecurrent path may be traced from source 734 through conductor 740, to thecenter tap of winding 717.

From this center tap the advance A current flows in two parallel pathsto the center tap of winding 720 of core 712. The first of these twopaths may be traced from the tap of winding 717, through the upperportion of winding 717 and then in parallel through non-linearresistance 724 and linear resistance 733 to the first and second endterminals respectively of winding 720, and then to the center tap ofwinding 720. The second of these two pathsmay be traced from the centertap of winding 717 of core 713 through the lower portion of winding 717,then in parallel through linear resistance 730 and non-linear resistance727 to the two end terminals of winding 720 and then in parallel throughthe two portions of tapped winding 720 to the center tap of winding 720.From the center tap of winding 720 the advance A pulse flows throughwinding 840 to the center tap of winding 715 of core 711. From thecenter tap of winding 715 the advance A pulse current path separatesinto two paths. The first of these two paths may be traced from thecenter tap of winding 715, through the upper portion of winding 715,then in parallel through non-linear resistance 722 and linear resistance731 to junctions 736 and 737, and thence in parallel through the upperand lower portions of tapped winding 713 of core 71% to the center tapof winding 718. The second of these two paths may be traced from thecenter tap of winding 715 through the lower portion of winding 715, thenin parallel through non-linear resistance 725 and linear resistance 728to the junctions 736 and 737, and thereafter through the upper and lowerportions of tapped winding 718 of core 710 to the center tap of winding713. From the center tap of winding 713 the advance A pulse currentflows through winding 820 of core 714) and returns to the advance Apulse source 734.

The advance B pulse source current path may be traced from advance Bpulse source 735, through conductor 741, winding 850 of core 713 to thecenter tap of winding 716 of core 712. From the center tap of winding716 the current path can be traced to the center tap of winding 719 ofcore 711 in two current paths. The first of these paths comprises theupper portion of winding 716 and the parallel combination of non-linearresistance 723, linear resistance 732, and the upper and the lowerportions of winding 719. The second of these two paths comprises thelower portion of winding 716 and the parallel combination comprisingnon-linear resistance 726, linear resistance 729, and the upper andlower portions of winding 719. From the center tap of winding 719 theadvance B current pulse may be traced through winding 830 of core 711and back to the advance 13 pulse sources 735.

The relative values of the four elements of each Wheatstone bridgecircuit are so chosen that the bridge is substantially balanced in theabsence of an advance pulse A or B and in the presence only of thatcurrent which flows through each bridge circuit as a result of theapplication thereacross of that voltage which is induced across atransfer-loop winding, either output or input, when the core of suchwinding is switched from one state to the other. The bridge currentresulting from such induced voltage is referred to in the claims as thereference current. When an advance pulse flows through a bridge circuitthe non-linear resistances decrease considerably in ohmic value, thusunbalancing the bridge circuit. It a voltage is created across theterminals of an output winding 718, 719 or 720 when the associatedbridge circuit is unbalanced, a ditference of potential will be createdacross the input winding 715, 716 or 717 of the next adjacent core. Aswill be explained later, this difference can be suificiently large tocause the magnetic flux in the said next adjacent core to switch fromone polarity to the opposite polarity.

The operation of the circuit shown in FIG. 12 will now be described.Assume that a pulse has been applied to input winding 714 which causescore 710 to have a condition of positive remanence as indicated by thedirection of the arrow 759 and which condition is herein arbitrarilydesignated to represent a binary bit of 1. Assume further that cores711, 712 and 713 are in a condition of negative remanence as indicatedby a direction opposite to the direction of the arrows 760, 761 and 762and which condition is herein defined as representing binary bits of 0."

If now an advance A pulse is applied to conductor 740, the binary bit of0 contained in core 712 will be transferred to core 713 and the binarybit of 1 contained in core 710 will be transferred to core 711. When theadvance A pulse fiOWs from the center tap of winding 717 through thebridge'eircuit to the center tap of winding 720, the non-linearresistances 724 and 727 in the bridge circuit decrease in value and thebridge circuit becomes unbalanced. Consequently, any difference ofpotential developed across the end terminals of winding 720 will cause adifference of of potential across the end terminals of winding 717. Theadvance A pulse con tinues to flow through winding 840 of core 712 andcauses the core 712 to become negatively saturated. However, since thecore 712 is already in a condition of negative remanence, the magneticflux change occurring in core 712 is insufiicient to cause a largeenough induced voltage across the end terminals of winding 720 to causeany appreciable change of magnetic flux in core 713. Thus it can be seenthat the binary bit of 0 contained in core 712 has been effectivelytransferred to core 713.

The advance A pulse flows through conductor 742 to the center tap ofwinding 715. When the advance A current pulse flows from the center tapof winding 715, through the bridge circuit, to the center tap of winding718, the bridge circuit becomes unbalanced due to the fact that theresistance of non-linear resistors 722 and 725 decreases appreciablywith the flow of the advance A pulse current therethrough. Consequently,if a difference of potential is created across the end terminals ofwinding 718, a difference of potential will appear across the endterminals of winding 715. Thus, when the advance A pulse current flowsthrough winding 820 to cause the magnetic flux in core 710 to switchfrom a positive remanence condition to a negative saturation condition,a voltage will be induced in winding 718 of sufficient magnitude tocause a current flow through the winding 715 of core 711 which will belarge enough to switch the magnetic flux in core 711 from a condition ofnegative remanence to a condition of positive saturation. Upontermination of the advance A pulse the magnetic flux in core 711 willrelax to a condition of positive remanence which represents a binary bitof 1. Thus the binary bit of 1 stored in core 710 has been effectivelytransferred to the core 711 leaving the core 710 containing a binary bitof 0.

In a similar manner the subsequent application of an advance B pulse canbe applied on conductor 741 to cause the information stored in cores 711and 713 to be transferred to core 712 and to a load or utilizationcircuit 780 respectively.

Though not immediately apparent, the flow of the advance current in thecoupling circuit which unbalances the bridge will have no effect oneither core coupled together by the given coupling circuit. Consider thecoupling circuit shown between cores 710 and 711 of FIG. 12. Assume thatan advance pulse is applied on conductor 742. This advance pulse willflow to the center tap of winding 715 and then flow in parallel throughthe two portions of winding 715 toward the points 738 and 739 of thebridge circuit. Each of the currents flowing toward the points 738 and739 from the winding 715 on core 711 has two paths presented to it. Oneis the high impedance path through resistor 731 or resistor 728 and theother is the low impedance path (when a current is passing therethrough)through non-linear resistor 722 or non-linear resistor 725. Each ofthese two currents is similarly affected by the presence of the winding718 across points 736 and 737. Therefore, the currents flowing towardpoints 738 and 739 must be equal, and consequently the net effect of theadvance current on core 711 is zero. from points 736 and 737 receives acontribution from two sources. One of these two sources is the highimpedance source, resistors 72.8 and 731 and the other of the twosources is the low impedance source, non-linear resistance 722 andnon-linear resistance 725. As a result, the currents flowing away frompoints 736 and 737 are equal. Therefore, the net effect of the advancecurrent on core 710 is zero.

It is to be understood that examples of the invention herein shown anddescribed are but preferred embodiments of the same and that variouschanges may be made in circuit arrangement, component values, sizes andmaterials without departing from the spirit or scope of the invention.

I claimz 1. A magnetic shift register comprising a plurality of magneticcores arranged in a row, each of said cores exhibiting stable magneticremanent states, a plurality of coupling circuits each individuallycoupling together adjacent ones of said plurality of magnetic cores,each of said coupling circuits comprising a tapped output winding on atransmitting magnetic core, a tapped input winding on the nextsucceeding receiving magnetic core in said row, a first asymmetricalconducting device associating a first end terminal of said tapped outputwinding with a first end terminal of said tapped input winding, a secondasymmetrical conducting device associating the second end terminal ofsaid tapped output winding with the second end terminal of said tappedinput winding, said first and second asymmetrical constructing devicesbeing directed to pass current more readily toward end terminals of thesame winding, a plurality of advancing windings each individually woundon one of said magnetic cores, each of said advancing windings beingconnected to the tap of one of the windings of the next succeedingcoupling circuit, and means to apply an electrical current pulse flowthrough the advance windings.

2. A magnetic shift register in accordance with claim 1 comprising aplurality of resistive means, individual ones of which are connected inseries with individual ones of said first and second asymmetricalconducting devices.

3. A magnetic shift register in accordance with claim 1 in which saidfirst tapped windings and said second tapped windings are center tappedwindings.

4. A magnetic device comprising a plurality of magnetic cores arrangedin a row, each of said cores exhibiting stable magnetic remanent statesand a plurality of Similarly, each of the currents flowing away saidfirst and second tapped windings together in such a manner that therespective anodes of said first and second asymmetrical conductingdevices are presented to end terminals of the same winding, a pluralityof advance windings each individually wound on respective ones of, saidplurality of magnetic cores, each of said advance windings beingconnected to the one of the tapped windings of the next succeedingmagnetic core, and means to apply an electrical current impulsesimultaneously through v alternate ones of the coupling circuits andtheir assocciatcd advance windings.

5. A magnetic device in accordance with claim 4 in which each of saidfirst tapped output windings and each of said second tapped inputwindings is a center tapped winding.

6. A magnetic device in accordance with claim 4 comprising a secondplurality of coupling circuits coupling together adjacent ones of saidmagnetic cores and each com prising a third tapped output winding on agiven core in said row, a fourth tapped input winding on the immediatelypreceding magnetic core in said row, a third asymmetrical conductingdevice connecting a first end terminal of said third output winding to afirst. end terminal of said second input winding, and a fourthasymmetrical conducting device connecting the second end terminal ofsaid third tapped output winding to the second end terminal of the saidfourth tapped input Winding, a further plurality of advancing windingseach individually wound on one of said magnetic cores, said furtheradvancing windings be-t ing connected to the tap of one of windings ofthe imme diately preceding magnetic core in said row, and further meansto apply current pulses simultaneously through 111- ternate ones of saidsecond plurality of coupling circuits I and their associated advancingwindings.

' 7. A reversible magnetic shift register comprising a plurality ofmagnetic cores arranged in a row, each of said. cores exhibiting stablemagnetic remanent states, a first plurality of coupling circuits eachindividually coupling together adjacent ones of said plurality ofmagnetic cores, each of said first plurality of coupling circuitscomprising a tapped output winding on a given core in said row and atapped'input winding on the next succeeding magnetic core in said row, afirst asymmetrical conducting device and a sec-0nd asymmetricalconducting device respectively associating first end terminals andsecondend te minals of said output and input tapped windings together insuch a manner that the respective anodes of said first and secondasymmetrical conducting devices are presented to end terminals of one ofsaid tapped windings, a plurality of advancing windings eachindividually wound on one of said plurality of magnetic cores, each ofsaid ad- I vancing windings being connected to the tap of one of thetapped windings of the next succeeding magnetic core, first means toapply an electrical pulse on a terminal of said advancing winding woundon the first, I magnetic core in said row, and second means to apply ana electrical pulse on a terminal of the advancing winding ducting deviceand a fourth asymmetrical conducting device respectively coupling firstand second end terminals 7 of said further tapped output and inputwindings together in such a manner that the respective anodes of saidthird and fourth asymmetrical conducting devices are individuallypresented to the end terminals of one of the further tapped windings, aplurality of further advnacing winding means each individually wound onone of said magnetic cores, each of said further advancing windingsbeing connected to the tap of one of the further tapped windings of theimmediately preceding magnetic core, means to apply an electrical pulseon a terminal of the further advancing winding means of the lastmagnetic core in said row, and means to apply an electrical pulse on aterminal; of the further advance winding means of the next to lastmagnetic core in said row.

8. A magnetic shift register comprising a plurality of magneticelements, each exhibiting stable magnetic remanent states a plurality ofcoupling circuits arranged to individually couple together said magneticelements in a row, each of said coupling circuits comprising a firsttapped output winding on a given magnetic core, a second tapped inputwinding on the next adjacent magnetic core, a first asymmetricalconducting device connected between a first end terminal of said firsttapped winding being connected to a first end terminal of said secondtapped winding, a second asymmetrical conducting device connectedbetween a second end terminal of said first tapped winding to a secondend terminal of said second tapped winding, a plurality of thirdwindings each individually wound on individual ones of said magneticcores, first terminals of each of said third windings being individuallyconnected to the tap of a tapped winding on one magnetic core, secondterminals of each of said third windings being individually connected tothe tap of a tapped winding on another magnetic core, and means tosimultaneously pass current pulses through at least a portion of saidthird windings and the corresponding taps of said tappe windings.

9. A magnetic shift register in accordance with claim 8 in which saidmeans to pass current comprises a first means and a second means,adapted to apply pulses simultaneously to the third winding on everyeven numbered magnetic core in said row and to the associated couplingcircuits, and a second means adapted to apply pulse simultaneously tothe third winding on every odd numbered magnetic core in said row and tothe associated coupling circuits.

10. A magnetic device comprising a first magnetic core and a secondmagnetic core, each of said magnetic cores exhibiting stable magneticremanent states and each having at least one output winding with anoutput winding on the first core being tapped, a further winding on eachof the cores with at least the further winding on the first core havingone of its terminals connected electrically to the tap of the tappedoutput winding on such core, an input winding on said first of saidmagnetic cores, :1 tapped input winding on the said second magnetic c e,the end terminals of said tapped output winding of said first magneticcore being coupled with the end terminals of said tapped input windingof said second magnetic core, and means to selectively apply aconditioning current pulse to the tap of one of the output windings onthe first core while separately energizing said further windings aboutsaid first core.

11. A magnetic shift register comprising a plurality of magnetic coresarranged in a row, each of said cores eX- hibiting stable magneticremanent states; a plurality of coupling means each individuallycoupling together adjacent ones of said plurality of magnetic cores;each of said coupling means comprising a tapped output winding on agiven magnetic core, a tapped input winding on the next succeedingmagnetic core in said row, a transfer circuit coupling the input andoutput windings, asymmetrical conducting means in the transfer circuitconnected to prevent currcnt from circulating in the transfer circuit inresponse to potentials generated in said input and output windings, andmeans for passing current from an external source through theasymmetrical conducting means and the tap on said input and outputwindings-to condition the transfer circuit for transfer of informationwhen a change of remanence state is effected in said given magneticcore.

12. A magnetic device comprising a first and a second static magneticstorage core each exhibiting stable magnetic remanent states and eachhaving at least one tapped winding, means for establishing apredetermined remanence condition in each core, means for selectivelyentering information in at least one core of a remanence conditionopposite the predetermined condition, a circuit coupling the ends of atapped winding upon each core, and means for passing current from thecenter taps through two parallel paths in said tapped windings toestablish substantially opposing magnetic flux in each core during thestatic condition of the cores.

13. A device as defined in claim 12 wherein the coupling circuitincludes asymmetrical conducting means for preventing circulatingcurrent flow in the coupling circuit in response to potentials inducedin the tapped windings when a remanence condition is established in oneof the cores.

14. A transfer loop for coupling two static magnetic storage elementseach exhibiting stable remanent states, comprising in combination, anoutput winding on a first one of said elements and an input winding onthe second one of said elements, at least one of said windings beingtapped at an intermediate point along its length, a coupling circuitconnected between said first and second windings for providing twobranch paths in said transfer loop, one path including at least aportion of both of said windings and the other including at least aportion of said at least one tapped winding, means connected to the tapof said tapped winding for passing current flow from an external sourcethrough both of said branch paths when the elements are in a staticcondition, and means including said output winding for inhibitingcurrent flow from said source in one of said branch paths in response toa dynamic flux switching operation in said first element.

15. A transfer loop as defined in claim 14 including means forselectively passing current flow through said branch paths toconditionally enable the loop to transfer information between saidelements.

16. A transfer loop as defined in claim 15 wherein said tapped windingis for establishing a predetermined remanence condition in one of theelements.

17. A system for conditionally transferring information between twostatic magnetic elements each exhibiting stable magnetic remanent statescomprising means for establishing opposing magnetic fluxes in at leastone of said elements when the elements are in a static condition, andmeans for unbalancing the magnetic flux in said one element in suchmagnitude and direction in response to the change of the staticremanence state in the other element that the information in said otherelement is transferred to said one element.

18. A system as defined in claim 17 wherein the means for establishingopposing magnetic fiux comprises tapped windings on each element, and acoupling circuit linking the two tapped windings by a pair ofasymmetrical conducting devices poled to prevent circulating current inthe coupling circuit solely in response to potentials induced in eitherof said tapped windings.

19. A system as defined in claim 17 wherein the means for establishingopposing magnetic flux comprises a tapped winding on at least said oneelement, an external current source coupled to the tap of said winding,and means proportioning the current fiow in the two sections of thetapped winding so that the opposing flux components are substantiallyequal in magnitude.

20. In combination, a pair of magnetic storage elcments each exhibitingstable magnetic remanent states and a transfer loop connectedtherebetween including a tapped winding on one element connected by twoleads to a pair of asymmetrical conductors connected in said two leadsof the transfer loop to pass current in the same direction along bothleads from one of the elements to the other element, means for passingenabling current through the asymmetrical conductors to the tap on saidtapped windings to condition the loop for passing signals from oneelement to another, and means for biasing one of said asymmetricalconductors in a direction tending to inhibit the enabling current flowtherethrough in response to the remanent state of one of said elements.

21. A loop as defined in claim 20 wherein the biasing means comprises awinding about one of said elements being connected in the enablingcurrent flow path, and means causing a change of remanence condition inthe last mentioned element in such a direction that the potentialinduced therefrom in said winding comprises the bias for said oneasymmetrical conductor.

22. A reversible magnetic shift register comprising a plurality ofpermanent storage cores and a plurality of temporary storage cores, eachof said cores having two stable storage states of magnetic remanence forstoring binary information, one of which is a first or reference stateand the other a second state, each of said cores further having a firstinput winding and a first output winding coupled to said core fortransferring information from one core to the next in a first direction,each of said cores also having a second input winding and a secondoutput winding for transferring information from one core to the next ina reverse direction, said permanent storage cores each having at least asingle switching winding for establishing said reference state duringfirst time periods and said temporary storage cores each having at leasta single switching winding for establishing said reference state duringsecond time periods, said first output winding of one of said permanentstorage cores connected to said first input winding of one of saidtemporary storage cores so as to form a closed circuit transfer loopbetween said permanent and said ternporary storage cores fortransferring information pulses in said first direction, said secondoutput winding of said temporary storage core connected to said secondinput winding of said permanent storage core so as to form a secondclosed circuit transfer loop between said permanent and said temporarystorage cores for transferring information in said reverse direction,transfer source means connected to each of said transfer circuits at twoseparate points to form between said two points in each of said transfercircuits'two parallel current paths for current from said transfersource means, one of said parallel paths including at least a portion ofthe output winding of the respective transfer circuit and the otherincluding at least a portion of the input Winding of said respectivetransfer circuit, means for selectively applying the current from saidtransfer source means to one of said transfer circuits to cause atransfer of information along said, register in one direction or theother, means including the output winding in the selected transfercircuit for diverting transfer current flow through said selectedtransfer circuit away from the parallel path including said portion ofthe output winding and into the parallel path including said portion ofthe input winding to cause an unbalance of transfer current flow in therespective parallel paths of said transfer circuit and a resultantchange of state of the core which includes the input winding of theselected transfer circuit only when the core'which includes the outputwinding of that circuit is in its second storage state.

23. A reversible magnetic shift register comprising a plurality ofstorage cores arranged in succession, each having two stable storagestates of magnetic remanence for storing binary information, one ofwhich is a first or reference state and the other a second state, eachof said cores further having a first input winding and a first outputWinding coupled to said core for transferring information from one coreto the next in a first direction,

nected to said second input winding of the preceding storage core insaid succession so as to form second closed v circuit transfer loopsbetween successive storage cores for transferring information in saidreverse direction, transfer source means connected to each of saidtransfer circuits at two separate points to form between said two pointsin each of said transfer circuits two parallel current paths for currentfrom said transfer source means, one of said parallel paths including atleast a portion of the output winding of the respective transfer circuitand the other including at least a portion of the input winding of saidrespective transfer circuit, means for selectively applying the currentfrom said transfer source means to one of said transfer circuits tocause a transfer of information along said register in one direction orthe other, means including the output winding in the selected transfercircuit for diverting transfer current flow through said selectedtransfer circuit away from the parallel path including said portion ofthe output winding and into the parallel path including said portion ofthe input winding to cause an unbalance of transfer current fiow in therespective parallel paths of said transfer circuit and a resultantchange of state of the core which includes the input winding of theselected transfer circuit only when the core which includes the outputwinding of that circuit is in its second storage state.

24. A transfer loop having two parallel branch paths coupling twomagnetic storage elements each having transformer windings thereon, saidelements having a siibstantially rectangular hysteresis loopcharacteristic, means forproviding current flow in both paths of saidloop, and

winding means for producing a flux change in one of said elements toselectively inhibit the current flow in one of said paths of said loopin response to signals thereby generated in one of said transformerwindings.

25. A transfer loop connecting two magnetic storage output winding forselectively biasing said asymmetrical I conductor to inhibit flow ofcurrent from said externalsource in one of said current paths inresponse to the' dynamic switching of said one of said elements from oneof its binary states to the other, resulting in an unbalance of flux insaid other element of enough magnitude to cause said other element toswitch from one binary state to another.

26. Means for transferring information from one magnetic storage binaryelement having a substantially square hysteresis loop characteristic toanother similar element comprising in combination, an output windingassociated with one element and an input winding associated with theother element, a transfer loop coupling said windings, said transferloop including two branch current paths, an external current source forpassing current through said two paths and through said input winding tocreate substantially equal and opposite magnetic firm in said otherelement, a diode coupled in the transfer loop, means including saidoutput winding for selectively biasing said diode to inhibit currentflow in one of said paths, and means for effecting transfer ofinformation between said elements in response to inhibited current fiowthrough the diode, said inhibited current flow resulting in an unbalanceof said equal and opposite fiux of enough magnitude to cause said otherelement to switch from one binary state to another.

27. A magnetic device comprising at least first and second saturablecore elements, each exhibiting stable magnetic remanent states, acurrent path having two sections in parallel, the first sectionincluding a first winding on the first element, the second sectionincluding a winding on the second element, means for applying a voltagedrop across said path to cause current to fiow therein, the said firstwinding on the first element being arranged to generate during shift ofthe first element a voltage which is in opposition to current flow insaid first section, means including a transfer winding on the firstelement for carrying a transfer current coexisting in time with thefirst mentioned current, the arrangement being such that transfercurrent in said transfer winding in amount sufiicient to but in adirection against shift of the first element will cause the current insaid path to divide due to low induced back voltage in the first windingof the first element between said two sections with insuttlcient currentin the second section to shift the second element, and transfer currentin amount sufficicnt to and in a direction to shift the first elementwill cause the current in the path to divide due to higher back voltageinduced in said first winding of said first element between said twosections with sutficient current in the second path to shift the secondelement.

28. A device as in claim 27 wherein the transfer winding on the firstelement is connected in the current path beyond the sections thereof.

29. A device as in claim 27 wherein each section of the current pathincludes a unidirectional conducting device connected to conduct in thesame direction in the respective sections to prevent loop currents inthe respective windings during operation of the device.

30. An electrical circuit comprising a magnetic core exhibiting stablemagnetic remanent states having a plurality of windings thereon, saidwindings including an input winding, an output winding, and an advancewinding, first unidirectional current means connected in series withsaid output winding, load means, second unidirectional current meansconnected in series with said load means, said load means and secondunidirectional means being connected in parallel across said outputwinding and said first unidirectional current means, and meansconnecting said advance winding to said paralleled output winding andload means.

31. An electrical circuit comprising a magnetic core exhibiting stablemagnetic remanent states having a plurality of windings thereon, saidwindings including an input. an output, and an advance winding, a firstunidirectional current element connnected in series with said outputwinding, load means, a second unidirectional current element connectedin series with said load means, said lead means and said secondunidirectional current element being connected in shunt across saidoutput winding and said first unidirectional current element, and meansfor and applying a pulse to said output winding and for simultaneouslyapplying a pulse to said advance winding for switching the direction ofmagnetization of said core.

32. A magnetic shift register comprising a first plurality of magneticcores, a second plurality of magnetic cores, said first and secondplurality of magnetic cores being arranged alternately in an electricalrow and each capable of assuming either of two stable states of magneticrcmanence, a first tapped winding on each of said magnetic cores otherthan said first magnetic core in said row, a second winding on each ofsaid cores, first terminals of each of said second windings beingconnected to first end terminals of the tapped windings of the magneticcores next succeeding in said electrical row, a plurality of firstcircuit means each comprising a first asymmetrically conducting devicehaving first and second electrodes and a first resistive means connectedin series with said electrodes, :1 first one of said electrodes of eachof said first asymmetrically conducting devices being connected to anindividual one of the second terminals of said second windings, aplurality of second circuit means each comprising a secondasymmetrically conductive device having two electrodes and a secondresistive means coupled in series with the electrodes, a first one ofsaid electrodes of each of said second asymmetrically con ductivedevices being connected to an individual one of the second end terminalsof said first windings, a plurality of common junction points, one eachof said common junction points joining together the circuit includingsaid second resistive means associated with a given one of saidplurality of first windings with the circuit including said firstresistive means associated with the one of said second windings of thenext preceding one of said plurality of magnetic cores, all except thefirst and second of said junction points in said row of cores beingconnected to the tap of the said first winding associatcd with themagnetic core immediately preceding the magnetic cores associated withsaid junction point, a first means adapted to apply an electrical pulseto the tap of the first winding associated with the last magnetic corein said electrical row, and a second means adapted to apply anelectrical pulse to the tap of the first winding associated with thenext to last magnetic core in said electrical row.

33. A magnetic shift register comprising a first plurality of magneticcores, a second plurality of magnetic cores, said first and secondpluralities of magnetic cores being individually arranged in alternatemanner in an electrical row and each of said cores being capable ofassuming either of two stable states of magnetic remanence, a pluralityof coupling circuits, one each of said coupling circuits joiningtogether adjacent ones of said magnetic cores, each of said couplingcircuits comprising a first winding on a given one of said magneticcores, a second tapped winding on the next adjacent magnetic core, firstcircuit means connecting a first terminal of said first winding and afirst end terminal of said second tapped winding, and second circuitmeans connecting the second terminal of said first winding and thesecond end terminal of said second tapped winding, said first circuitmeans comprising a first asymmetric-ally conducting device having ananode and a cathode, a second asymmetrically conducting device having ananode and a cathode, a first resistance, and a second resistance allconnected in a series arrangement such that the anode of said firstasymmetrical device is connected to the said second terminal of saidfirst winding and the anode of the said second asymmetrical device isconnected to the second end terminal of said second tapped winding, thejunction between each of said first and second resistive means beingconnected to the tap of the said second winding of the magnetic coreimmediately preceding the two magnetic cores coupled together by thecircuit means comprising the specific first and second resistive means,a first means to apply an electrical pulse to the center tap of thesecond winding on the last magnetic core in said row, and second meansto apply an electrical pulse to the tap of the second winding on thenext to last magnetic core in said row of magnetic cores.

34. A magnetic shift register comprising a plurality of magnetic coresarranged in an electrical row, each of said cores being capable ofassuming either of two stable states of magnetic. remanence, a firstplurality of coupling circuits adapted to couple together adjacent onesof said plurality of magnetic cores, each of said coupling circuitscomprising a first winding means wound on a given individual one of saidmagnetic cores and a second tapped 25 winding wound on the magnetic corenext succeeding said given magnetic core in said row of magnetic cores,a first terminal of said first winding means being connected to a firstend terminal of said second winding means, a circuit means comprising afirst asymmetrically conducting device having first and secondelectrodes, 21 second asymmetrically conductive device having first andsecond electrodes, a first resistive means, and a second resistive meansall connected in a series arrangement such that the first electrode ofsaid first asymmetrical means is connected to the second terminal ofsaid first winding means and the first electrode of said secondasymmetrical means is connected to a second end terminal of said secondtapped winding, a junction point between said series arrangementcircuits, a plurality of connecting means individually connecting eachof the said junctions to individual ones of the taps of the said secondwinding associated with the magnetic core immediately preceding the twomagnetic cores coupled together by the coupling means comprising saidjunction points, a first means to apply an electrical pulse to'the tapof the said second winding of the last magnetic core in said row, andsecond means to apply an electrical pulse to the tap of the said secondwinding of the next to last magnetic core in said row of magnetic cores.

35. A magnetic shift register in accordance with claim 34 comprising asecond plurality of coupling circuits adapted to couple togetheradjacent ones of said magnetic cores, each of said second plurality ofcoupling circuits comprising the same arrangement of circuit elements assaid first plurality of circuit elements, each of said second pluralityof elements being connected in reverse orderto that of said firstplurality of coupling circuits, :1 third means to cause the informationsignals represented by the magnetic storage states of the odd numberedcores to be advanced to the even numbered cores in said row of cores,and fourth means to cause the information signals represented by themagnetic storage states of the even numbered cores to be advanced to theodd numbered cores in said row of cores.

36. A reversible magnetic shift register comprising a plurality ofmagnetic cores arranged in an electrical row, each of said cores beingcapable of assuming either of two-stable states of magnetic remanence, aplurality of coupling circuits, each of said magnetic cores'beingcoupled to each adjacent magnetic core by two of said coupling circuits,a first of said two coupling circuits comprising a first winding meanswound on a given individual one of said magnetic cores and a secondtapped winding means wound on next succeeding one of said magneticcores, a second of said two coupling circuits comprising a second tappedwinding means wound on said given magnetic core and a second windingmeans wound on said next preceding magnetic core, first terminals ofsaid first and second winding means being connected to first endterminals of said first tapped winding and said second tapped windingrespectively, a plurality of circuit means, individual ones of saidplurality of circuit means connecting the second terminals of each ofsaid first and second windings to the second end terminals of theassociated first tapped winding and second tapped winding respectively,each of said circuit means comprising a first asymmetrically conductingdevice having an anode and a cathode, a second asymmetrically conductingdevice having an anode and a cathode, a first resistance, and a secondresistance connected in series arrangement in such a manner that theanode of said first asymmetrical device is connected to the said secondterminal of the associated winding means.

and the anode of said second asymmetrical device is connected to thesaid second end terminal of the associated tapped winding means, ajunction between the said first and second resistive means of each ofsaid plurality of circuit means, the junctions associated with thecoupling circuits comprising the associated first wind- 26 ing and theassociated first tapped windings being connected to the tap of the firsttapped winding associated with the magnetic core immediately precedingthe two magnetic'cores coupled together by the coupling circuitcomprising the associated junction, the junctions associated with thecoupling circuits comprising second wind-' ings and second tappedwindings being connected to the tap of the second tapped windingassociated with the magnetic core immediately following the two magneticcores coupled together by the coupling circuit comprising the associatedjunction, at third means adapted to apply electrical pulses upon the tapof the first tapped winding of the last magnetic core in said row, afourth means adapted to apply electrical impulses upon the tap of thefirst tapped winding of the next to last magnetic core in said row, afifth means adapted to apply electrical pulses to the tap of the secondtapped winding of the first magnetic core in said row, and a sixth meansadapted to apply electrical pulses to the tap of the second tappedwinding of the second magnetic core in said row.

37. A reversible magnetic shift register comprising a plurality ofmagnetic cores arranged in a row, each core being capable of assumingeither of two stable states of next succeeding magnetic core, a firstterminal of said first winding means being connected to a first endterminal of said first tapped winding, and a first circuit meansconnecting the second terminal-0t said first winding means to the secondend terminal of said first tapped winding, each of said second pluralityof coupling circuits comprising a second winding means wound on a givenmagnetic core and a second tapped winding means wound on the immediatelypreceding magnetic core, a first terminal of said second winding meansbeing connected to, a first end terminal of said second tapped, winding,a second circuit means connecting the second terminal of said secondwinding means to the second end-terminal of said second tapped winding,said first and second circuit means each comprising a first asym vmetrically conductive device, having an anode and a cathode, a secondasymmetrically conductive device hav- 7 associated tapped winding, ajunction between each ofi said first resistive means and said secondresistive means, each of the junctions associated with said firstplurality of coupling means being individually connected to the tap ofthe said second winding means immediately preceding the two magneticcores coupled together by the coupling means comprising the associatedjunction, each of the junctions associated with said second pluralityvof coupling means being individually connected to the tap of the saidsecond winding means of said second plurality of winding means of themagnetic core immediately succeeding the two magnetic cores coupledtogether by the coupling means comprising the associated junction, andfirst means adapted to selectively impress electrical impulses upon thetaps of the second tapped windings of said last magnetic core in saidrow and said next magnetic cores arranged in a row, each of said coresbeing capable of assuming either of two stable states of magneticremanence, a plurality of coupling circuits each individual-ly couplingtogether adjacent ones of said magnetic cores, each of said couplingcircuits comprising a first winding on a given one of said magneticcores, a second tapped winding on the next adjacent magnetic core, afirst terminal of said first winding being connected to a first endterminal of said second tapped winding, and a fir-st circuit mean-sconnecting the second terminal of said first winding to the second endterminal of said second tapped winding, said circuit means comprising ajunc tion point, a first asymmetrically conductive device, and a secondasymmetrically conductive device having an anode and a cathode, saidfirst asymmetrical device connecting said junction point to said secondterminal of said first winding, said second asymmetrical deviceconnecting the said junction point to the said second terminal of saidsecond tapped winding, the polarities of said first and secondasymmetrical devices being arranged so that similar impedances arepresented to said junction point, each of said junctions being connectedto the tap of the said second winding of the magnetic core immediatelypreceding the two magnetic cores coupled together by the circuit meanscomprising the associated junction, a first means to apply an electricalpulse to the center tap of the second tapped winding on the lastmagnetic core in said row, and second means to apply an electrical pulseto the tap of the second tapped winding on the next to last magneticcore in said row of magnetic cores.

39. A reversible magnetic shift register comprising a plurality ofmagnetic cores arranged in a row, each of said cores being capable ofassuming either of two stable states of magnetic remanence, a firstplurality of coupling circuits and a second plurality of couplingcircuits, one of said first plurality of coupling circuits and one ofsaid second plurality of coupling circuits coupling together successiveones of said magnetic cores, each of said coupling circuits comprising afirst winding on a given one of said magnetic cores, a second tappedwinding on an adjacent one of said magnetic cores, a first terminal ofsaid first winding being connected to a first end terminal of saidsecond tapped winding. and a first circuit connecting the secondterminal of said first winding to the second end terminal of said secondtapped winding, said circuit means comprising a first asymmetricallyconductive device having an anode and a cathode, a second asymmetricallyconductive device having an anode and a cathode, and a junction point,said first asymmetrical device connecting said junction point to saidsecond terminal of said first winding, and said second asymmetricaldevice connecting said junction point to the said second end terminal ofsaid second tapped winding, the said adjacent magnetic core with respectto the said first plurality of coupling circuits being the nextsucceeding magnetic core in said row, the said adjacent magnetic corewith respect to said second plurality of coupling circuits being theimmediately preceding magnetic core in said row, each of said junctionsof said first plurality of coupling circuits being connected to the tapof the said second tapped winding of the magnetic core immediatelypreceding the two magnetic cores coupled together by the couplingcircuit comprising the associated junction point, each of the junctionsof said second plurality of coupling circuits being connected to the tapof the said second tapped winding of the magnetic core immediatelysucceeding the two magnetic cores coupled together by the couplingcircuit comprising the associated junction point, and means toselectively apply electrical pulses to the taps ofsaid second tappedwindings.

40. A reversible magnetic shift register comprising a row of magneticcores, each of said cores being capable of assuming either of two stablestates of magnetic remanence, a first plurality of coupling means, eachof said first plurality of coupling means comprising a first outputwinding on a given core in said row of cores and a first split inputwinding on the next subsequent magnetic core, a first means to advancein a first direction the information signals represented by the magneticstorage states of the odd numbered cores to the even numbered cores insaid row of magnetic cores, :1 second means to advance in said firstdirection the information signals represented by the magnetic storagestates of the even numbered cores to the odd numbered cores, a secondplurality of coupling means, each of said second plurality of cou plingmeans comprising a second output wind-ing on a given magnetic core and asecond split input winding on the next preceding magnetic core, a thirdmeans to ad vance in the direct-ion reversed to that of said firstdirection the information signals represented by the magnetic storagestates of said odd numbered cores to said even numbered cores, and :afourth means to advance in the direction reverse to that of said firstdirection theinformation signals represented by the magnetic storagestates of said even numbered cores to said odd numbered cores.

41. A magnetic shift register comprising an array of binary magneticelements, each of said elements being capable of assuming eitherof twostable states of magnetic remanence, a transfer loop coupling each pairof such. immediately adjacent elements comprising an untapped outputwinding on the first element of the pair and a tapped input winding onthe second element of said pair, the terminals of said output windingjoined to end terminals of said tapped input winding, a pair ofasymmetrically conducting devices connected in said transfer loop toeach second terminal of said input and oriented in a direction tocurrent flow inhibit circulating and means to pass advancing currentthrough said transfer loop, the tap of the input winding and a junctionpoint intermediate said asymmetrically conducting devices being thepoints of entry and exit for the advancing current through said transferloop. 7

42. A magnetic signal transfer loop comprising two bistable magneticswitching elements, each of said elements being capable of assumingeither of two stable states of magnetic remanence, output winding on afirst of said elements, a pair of input windings on a second of saidelements, a pair of diodes coupling the input windings with the outputwinding to pass current in the transfer loop coupling circuit from oneelement to the other, a circuit connection between said input windings,means for passing current into said connection to thereby pass currentinto two branch cur-rent paths each including one of said input windingsand one including at least a portion of said output winding for causingsubstantially balanced magnetic flux in said input windings in thestatic condition of said elements and for causing enough flux unbalancein the second said element upon a dynamic switching of the first elementin one direction to cause the second element to switch from one stableposition to the other.

43. The invention claimed in claim 42 wherein the diodes are coupled ina single lead connecting a terminal of said output winding to a terminalof one of said input windings.

44. First and second magnetic cores each capable of assuming either oftwo stable states of magnetic remanence, one of said states beingconsidered a reference state; an input winding on said first core whichwhen encrgized by a pulse of current switches or tends to switch saidfirst core to the state other than said reference state; an outputwinding on said first core in which a voltage is induced when said firstcore switches from either of said states to the other; a transfer loopcoupling said first and second cores, said transfer loop including saidfirst-core output Winding, an input winding on said second core, and apair of asymmetrically current conducting devices, said second-coreinput winding having a tap at an intermediate point, said asymmetricallycurrent conducting devices being connected in opposing manner in saidtransfer loop to inhibit current flow around said loop and therebyprevent the said induced voltage in said first-

36. A REVERSIBLE MAGNETIC SHIFT REGISTER COMPRISING A PLURALITY OFMAGNETIC CORES ARRANGED IN AN ELECTRICAL ROW, EACH OF SAID CORES BEINGCAPABLE OF ASSUMING EITHER OF TWO STABLE STATES OF MAGNETIC REMANENCE, APLURALITY OF COUPLING CIRCUITS, EACH OF SAID MAGNETIC CORES BEINGCOUPLED TO EACH ADJACENT MAGNETIC CORE BY TWO OF SAID COUPLING CIRCUITS,A FIRST OF SAID TWO COUPLING CIRCUITS COMPRISING A FIRST WINDING MEANSWOUND ON A GIVEN INDIVIDUAL ONE OF SAID MAGNETIC CORES AND A SECONDTAPPED WINDING MEANS WOUND ON NEXT SUCCEEDING ONE OF SAID MAGNETICCORES, A SECOND OF SAID TWO COUPLING CIRCUITS COMPRISING A SECOND TAPPEDWINDING MEANS WOUND ON SAID GIVEN MAGNETIC CORE AND A SECOND WINDINGMEANS WOUND ON SAID NEXT PRECEDING MAGNETIC CORE, FIRST TERMINALS ANDSAID FIRST AND SECOND WINDING MEANS BEING CONNECTED TO FIRST ENDTERMINALS OF SAID FIRST TAPPED WINDING AND SAID SECOND TAPPED WINDINGRESPECTIVELY, A PLURALITY OF CIRCUIT MEANS, INDIVIDUAL ONES OF SAIDPLURALITY OF CIRCUIT MEANS CONNECTING THE SECOND TERMINALS OF EACH OFSAID FIRST AND SECOND WINDINGS TO THE SECOND END TERMINALS OF THEASSOCIATED FIRST TAPPED WINDING AND SECOND TAPPED WINDING RESPECTIVELY,EACH OF SAID CIRCUIT MEANS COMPRISING A FIRST ASYMMETRICALLY CONDUCTINGDEVICE HAVING AN ANODE AND A CATHODE, A SECOND ASYMMETRICALLY CONDUCTINGDEVICE HAVING AN ANODE AND A CATHODE, A FIRST RESISTANCE, AND A SECONDRESISTANCE CONNECTED IN SERIES ARRANGEMENT IN SUCH A MANNER THAT THEANODE OF SAID FIRST ASYMMETRICAL DEVICE IS CONNECTED TO THE SAID SECONDTER-